Question

I want to open a pop up window automatically (when I open my website) after a particular date that I mention in the function.

How can I assign date function? I want this window to be opened automatically on 27/07/2011 and after that whenever I open the website. Please suggest

<script type="text/javascript">
function newPopup(url) {
popupWindow = window.open(
           url,'popUpWindow','height=600,width=605,left=4,top=4,resizable=no,scrollbars=no,toolbar=no,menubar=no,location=no,directories=no,status=yes')
  }
    </script>

Answer 1

<script type="text/javascript"> 
    function newPopup(url) {
      popupWindow = window.open(url,'popUpWindow','...');
    }

    var date = new Date();
    var formatedDate = date.getDate()+"/"+(date.getMonth()+1)+"/"+date.getFullYear();

    if (formatedDate == "27/07/2011 ") {
       newPopup("http://example.com");
    }
</script> 

Make note that popup blockers will automatically block this window.
Most popup blockers only allow popups if they are triggered by the user, for example by a click.

Triggering the popup using on click event:

<a href="#" onclick="newPopup('http://example.com'); return false;">
     Click Here to open pop up window
</a>

when the user click on the link, the function newPopup is triggered and your popup opens.